An ecological classification of the burrows of Australian freshwater crayfish

1986 ◽  
Vol 37 (2) ◽  
pp. 237 ◽  
Author(s):  
PHJ Horwitz ◽  
AMM Richardson
Keyword(s):  
Water Table ◽  
North American ◽  
Freshwater Crayfish ◽  
Ecological Classification ◽  
The Third ◽  
Run Off ◽  
Burrowing Behaviour ◽  
Australian Freshwater

A classification of freshwater crayfish burrows, based on their relationship to the water-table, is presented. Burrows are divided into three classes, the third of which is apparently not found outside Australia and contains burrows which are independent of the water-table, receiving their water from surface run-off. The classification is compared with Hobbs classification of North American crayfish which is based on their burrowing behaviour.

A Note on Synchronized Emergence in Gomphus vastus Walsh (Odonata: Gomphidae)

1963 ◽  
Vol 95 (1) ◽  
pp. 69-69 ◽  
Author(s):  
Clifford Johnson
Keyword(s):  
North American ◽  
Adult Emergence ◽  
North American Species ◽  
Ecological Classification ◽  
General Area ◽  
River Bank ◽  
Dragonfly Species

An ecological classification of dragonfly species into spring and summer types was proposed by Corbet (1954). Much of the basis for the classification rests with the pattern and period of adult emergence. Since little information of this type is known for North American species, the following observations are reported.On May 20, 1962, I spent several hours collecting Baisaeschna janata and Didymops transversa along the New River, two miles north of McCoy, Virginia. A search was made at that time for odonate exuviae. None were found. I returned to the site at 9:30 a.m. the following day. The vegetation, tree trunks, rocks and detritus along the river were clustered with exuviae, all apparently of Gomphus vastus. Several thousand individuals must have emerged from that general area of the river. As an example of the density, 230 cast skins were counted along one 20-foot stretch of the river bank. Some individuals had transformed directly on the sand banks and others at a height of seven feet.

ABOUT THE PROBLEM OF CLASSIFICATION OF THE CONCEPTS OF INFORMATICS STUDIED AT SECONDARY SCHOOL

2018 ◽  
pp. 4-7
Author(s):  
S. I. Zenko
Keyword(s):  
Secondary School ◽  
Foreign Language ◽  
Computer Science ◽  
Parts Of Speech ◽  
The Third ◽  
The Cross ◽  
Definition Of

The article raises the problem of classification of the concepts of computer science and informatics studied at secondary school. The efficiency of creation of techniques of training of pupils in these concepts depends on its solution. The author proposes to consider classifications of the concepts of school informatics from four positions: on the cross-subject basis, the content lines of the educational subject "Informatics", the logical and structural interrelations and interactions of the studied concepts, the etymology of foreign-language and translated words in the definition of the concepts of informatics. As a result of the first classification general and special concepts are allocated; the second classification — inter-content and intra-content concepts; the third classification — stable (steady), expanding, key and auxiliary concepts; the fourth classification — concepts-nouns, conceptsverbs, concepts-adjectives and concepts — combinations of parts of speech.

(A review). BRAUN-BLANQUETIA. Recueil de travaux de geobotanique / review of geobotanical monographs. Vol. 46. Centenaire de la phytosociologie. CAMERINO, 2010. 423 p.

2011 ◽  
pp. 143-147
Author(s):  
L. G. Naumova ◽  
V. B. Martynenko ◽  
S. M. Yamalov
Keyword(s):  
Plant Association ◽  
Northern Asia ◽  
The Third ◽  
International Botanical ◽  
International Botanical Congress ◽  
History Of ◽  
Definition Of

Date of «birth» of phytosociology (phytocenology) is considered to be 1910, when at the third International Botanical Congress in Brussels adopted the definition of plant association in the wording Including Flaó and K. Schröter (Flahault, Schröter, 1910; Alexandrov, 1969). The centenary of this momentous event in the history of phytocenology devoted to the 46th edition of the Yearbook «Braun-Blanquetia», which began to emerge in 1984 in Camerino (Italy) and it has a task to publish large geobotanical works. During the years of the publication of the Yearbook on its pages were published twice work of the Russian scientists — «The steppes of Mongolia» (Z. V. Karamysheva, V. N. Khramtsov. Vol. 17. 1995), and «Classification of continental hemiboreal forests of Northern Asia» (N. B. Ermakov in collaboration with English colleagues and J. Dring, J. Rodwell. Vol. 28. 2000).

Irrigation of Geraniums with an Automatic Controlled Water Table System

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 522d-522 ◽  
Author(s):  
J.W. Buxton ◽  
D.L. Ingram ◽  
Wenwei Jia
Keyword(s):  
Water Potential ◽  
Leaf Area ◽  
Water Table ◽  
Nutrient Solution ◽  
Irrigation System ◽  
Central Area ◽  
Dry Weight ◽  
Trickle Irrigation ◽  
Run Off ◽  
Optimum Water

Geraniums in 15-cm pots were irrigated automatically for 8 weeks with a Controlled Water Table (CWT) irrigation system. Plants were irrigated with a nutrient solution supplied by a capillary mat with one end of the mat suspended in a trough below the bottom of the pot. The nutrient solution remained at a constant level in the trough. Nutrient solution removed from the trough was immediately replaced from a larger reservoir. The vertical distance from the surface of the nutrient solution and the bottom of the pot determined the water/air ratio and water potential in the growing media. Treatments consisted of placing pots at 0, 2, 4, and 6 cm above the nutrient solution. Control plants were irrigated as needed with a trickle irrigation system. Geraniums grown at 0,2 and 4 CWT were ≈25% larger than the control plants and those grown at 6 CWT as measured by dry weight and leaf area. Roots of plants grown at 0 CWT were concentrated in the central area of the root ball; whereas roots of plants in other treatments were located more near the bottom of the pot. Advantages of the CWT system include: Plant controlled automatic irrigation; no run off; optimum water/air ratio.

Phylogeny of the Australian freshwater crayfish Cherax destructor-complex (Decapoda : Parastacidae) inferred from four mitochondrial gene regions

2005 ◽  
Vol 19 (3) ◽  
pp. 209 ◽  
Author(s):  
Thuy T. T. Nguyen ◽  
Christopher M. Austin
Keyword(s):  
16S Rrna ◽  
Cytochrome Oxidase ◽  
Mitochondrial Gene ◽  
Large Subunit ◽  
Strong Support ◽  
Interspecific Variation ◽  
Rrna Gene ◽  
Freshwater Crayfish ◽  
Cherax Destructor ◽  
Australian Freshwater

The phylogenetic relationships among 32 individuals of Australian freshwater crayfish belonging to the Cherax destructor-complex were investigated using a dataset comprising sequences from four mitochondrial gene regions: the large subunit rRNA (16S rRNA), cytochrome oxidase I (COI), adenosine triphosphatase 6 (ATPase 6), and cytochrome oxidase III (COIII). A total of 1602 bp was obtained, and a combined analysis of the data produced a tree with strong support (bootstrap values 94–100%) for three divergent lineages, verifying the phylogenetic hypotheses of relationships within the C. destructor species-complex suggested in previous studies. Overall, sequences from the 16S rRNA gene showed the least variation compared to those generated from protein coding genes, which presented considerably greater levels of divergence. The level of divergence within C. destructor was found to be greater than that observed in other species of freshwater crayfish, but interspecific variation among species examined in the present study was similar to that reported previously.

Old Trails and New Directions: Papers of the Third North American Fur Trade Conference

Ethnohistory ◽  
1982 ◽  
Vol 29 (3) ◽  
pp. 221
Author(s):  
Shepard Krech ◽  
Carol M. Judd ◽  
Arthur J. Ray
Keyword(s):  
North American ◽  
Fur Trade ◽  
The Third ◽  
New Directions

Behavioural responses of Australian freshwater crayfish (Cherax cainii and Cherax albidus) to exotic fish odour

2006 ◽  
Vol 54 (6) ◽  
pp. 399 ◽  
Author(s):  
S. G. Height ◽  
G. J. Whisson
Keyword(s):  
Western Australia ◽  
Predatory Fish ◽  
Behavioural Plasticity ◽  
Current Debate ◽  
Freshwater Crayfish ◽  
Indigenous Species ◽  
Exotic Fish ◽  
Behavioural Responses ◽  
Invasive Crayfish ◽  
Australian Freshwater

Exotic finfish and crayfish have been translocated into Western Australia for more than 100 years. Deliberate stocking and subsequent escape from man-made impoundments have resulted in widespread distribution of non-native yabbies (Cherax albidus) and the exotic redfin perch (Perca fluviatilis) in the State’s south-west. Both species are considered invasive and are known to compete with indigenous species for resources. The nature and degree of impact on native marron (Cherax cainii) is unclear and the subject of current debate. Other researchers have hypothesised that invasive species modify their behaviour in the presence of predators in a more rapid and advantageous manner than native species. This greater behavioural plasticity can result in displacement of indigenous species and successful colonisation of invaders. The aim of this study was to investigate behavioural responses of an indigenous crayfish (C. cainii) and an invasive crayfish (C. albidus) to odours from a native predator (Tandanus bostocki) and an exotic predatory fish (P. fluviatilis) present in Western Australia. Crayfish behaviour was observed in individual glass tanks following the addition of odours from native (T. bostocki) or exotic (P. fluviatilis) finfish predators. Marron exhibited minor behavioural modifications when presented with odours from native or exotic finfish. In contrast, the invasive yabby showed greater detection of odours, displaying significant changes in behaviour (P < 0.05). Yabbies also appeared to distinguish between food odour (commercial crayfish feed) and predator odour; however, neither marron nor yabbies displayed behaviour indicating that they could distinguish between a native or exotic fish predator. Results support the hypothesis that invasive crayfish species have a greater capacity for behavioural plasticity than non-invasive crayfish.

The Aesthetic Earlobe: Classification of Lobule Ptosis on the Basis of a Survey of North American Caucasians

2003 ◽  
Vol 112 (1) ◽  
pp. 266-272 ◽  
Author(s):  
Arian Mowlavi ◽  
D. Garth Meldrum ◽  
Bradon J. Wilhelmi ◽  
Ashkan Ghavami ◽  
Elvin G. Zook
Keyword(s):  
North American ◽  
The Aesthetic

The biology of two species of Engaeus (Decapoda : Parastacidae) in Tasmania. III. Habitat, food, associated fauna and distribution

1977 ◽  
Vol 28 (1) ◽  
pp. 95 ◽  
Author(s):  
PJ Suter ◽  
AMM Richardson
Keyword(s):  
Dissolved Oxygen ◽  
Geographical Distribution ◽  
Water Table ◽  
Freshwater Crayfish ◽  
Associated Fauna ◽  
Water Table Level ◽  
Burrow Structure ◽  
Study Sites ◽  
North Western ◽  
Temperature Water

The habitats of two apparently sympatric freshwater crayfish, Engaeus cisternarius and E. fossor, in north-western Tasmania were compared. At two study sites data on rainfall, temperature, water table level, dissolved oxygen and pH were collected. E. fossor occupies regions below the water table, whilst E. cisternarius occupies drier areas above the water table. The burrow structure, burrow fauna, ectofauna and food were compared. The geographical distribution of each species is discussed.

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